Development of a porcine model for assessment of mucosal repair following endoscopic resection of the lower gastrointestinal tract.

BACKGROUND AND AIMS: Endoscopic mucosal resection (EMR) is widely performed for the treatment of colorectal polyps. However, the pathophysiological mechanisms of mucosal repair, including in situations at high risk of post-polypectomy bleeding, remain largely unknown. The objective of our study was to develop a porcine model of EMR in the lower gastrointestinal tract to monitor mucosal wound healing over time. METHODS: Under general anesthesia, five large wounds were created in the lower gastrointestinal tract at different times, i. e. at day 0, 3, 7, 10, and 14, by multiband EMR, in each of the six pigs in the study. A colorectal resection was performed at day 14 and the animal euthanized. Repeated endoscopic and endomicroscopic examination, and histological analysis were performed. RESULTS: No complications occurred and all animals reached the study end point. The endoscopic aspect of wound healing evolved into different phases with first a fibrin deposit covering the wounds which then gave way to granulomatous tissue. The size of the wound regressed significantly as early as day 3. Re-epithelialization of the wound started from day 7, and neo-mucosal crypts appeared from day 10. The endomicroscopic analysis described a 'ground glass appearance' from day 3 and irregular crypts from day 10, which was consistent with histological data. Good agreement between macroscopic, endomicroscopic, and histological parameters of mucosal wound healing was observed in vivo. CONCLUSION: This study demonstrates for the first time the feasibility of an experimental in vivo porcine model of lower gastrointestinal endoscopic resections to monitor tissue repair. This model might be helpful to document pharmacological approaches for preventing complications of endoscopic procedures performed in humans.

A novel hemostatic powder for upper gastrointestinal bleeding: a multicenter study (the "GRAPHE" registry).

Background and study aims: The hemostatic powder TC-325 (Hemospray; Cook Medical, Winston-Salem, North Carolina, USA) has shown promising results in the treatment of upper gastrointestinal bleeding (UGIB) in expert centers in pilot studies. The aim of this study was to evaluate the feasibility and efficacy of TC-325 in a large prospective registry of use in routine practice. Patients and methods: The data of all patients treated with TC-325 were prospectively collected through a national registry. Outcomes were the immediate feasibility and efficacy of TC-325 application, as well as the rates of rebleeding at Day 8 and Day 30. Multivariate analysis was performed to determine predictive factors of rebleeding. Results: A total of 202 patients were enrolled and 64 endoscopists participated from 20 centers. TC-325 was used as salvage therapy in 108 patients (53.5 %). The etiology of bleeding was an ulcer in 75 patients (37.1 %), tumor in 61 (30.2 %), postendoscopic therapy in 35 (17.3 %), or other in 31 (15.3 %). Application of the hemostatic powder was found to be very easy or easy in 31.7 % and 55.4 %, respectively. The immediate efficacy rate was 96.5 %. Recurrence of UGIB was noted at Day 8 and Day 30 in 26.7 % and 33.5 %, respectively. Predictive factors of recurrence at Day 8 were melena at initial presentation and use of TC-325 as salvage therapy. Conclusion: These multicenter data confirmed the high rate of immediate hemostasis, excellent feasibility, and good safety profile of TC-325, which could become the treatment of choice in bleeding tumors or postendoscopic bleeding but not in bleeding ulcers where randomized studies are needed. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02595853).